JP2005029767A - Pressure/temperature sensitive composite functional paint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure/temperature sensitive composite paint accurately and simultaneously measuring the pressure and the temperature of the same position on a model surface used for a practical window-tunnel test by providing a temperature sensitive paint having an emission wavelength of light without overlapping the emissionn spectrum of a pressure sensitive paint and covering a required temperature zone, and a combination of a binder material, expressing no uneven painting when painted by mixing the temperature sensitive paint with the pressure sensitive paint, and a solvent. <P>SOLUTION: The pressure/temperature sensitive functional paint is prepared by mixing a cumarin-based temperature sensitive pigment as the temperature sensitive material and a porphyrin having Pt or Pd as a central metal, which is a pressure sensitive pigment, as the pressure sensitive material, with a Poly-IBM-co-TFEM (poly-isobutyl methacrylate-co-trifluoroethyl methacrylate), a fluorine-based polymer, as the binder and using a paint thinner as the solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coating material that changes color development in response to pressure and temperature, and more particularly to a pressure- and temperature-sensitive composite coating material suitable for measuring the surface pressure and temperature field of a subject.

  A technique for measuring pressure distribution with a pressure-sensitive paint is known, and attempts have been made to measure pressure distribution on aircrafts and rocket bodies, mainly using a model in a wind tunnel. Conventionally, pressure distribution measurement in a model in a wind tunnel has been performed by measuring a number of pressure detection holes by opening a large number of pressure detection holes on the model surface. In that case, the number of holes that can be provided in the model surface is structurally limited, but pressure distribution measurement using this pressure-sensitive paint is applied to the model surface and the luminescence corresponding to the pressure at that part is observed. Therefore, there is no limitation as described above, and there is a feature that fine local data on the entire surface can be obtained as image information using a CCD camera or the like.

  The principle of pressure measurement using this pressure-sensitive paint is the luminescence (fluorescence / phosphorescence) emitted by chemical substances such as porphyrins (PtTFPP, PtOEP, PdTFPP, etc.) with platinum or palladium as the central metal depending on the partial pressure of oxygen. It measures from the light emission state using the phenomenon. This light emission phenomenon is described in Non-Patent Document 1 as follows. That is, when this chemical substance receives excitation light, electrons in the ground state absorb light energy and transition to a high energy state. This excited state is divided into a singlet state (S1) and a triplet state (T1) depending on the spin state of electrons, and the transition from S1 to T1 occurs by conversion of internal energy. The path from the excited state to the ground state includes a phenomenon involving light irradiance and a phenomenon without irradiance. In the former case, the energy difference eV has a relationship of eV = hν (where h is a Planck's constant). In the latter case, the light is converted into energy other than light, so that the luminescence phenomenon is not exhibited. The luminescence from S1 to the ground state becomes fluorescence, and the luminescence from T1 to the ground state becomes phosphorescence. Fluorescence and phosphorescence are distinguished by the difference in decay time. Fluorescence that does not emit light immediately when excitation is stopped and that that emits light for a while even after excitation is stopped is called phosphorescence. In the phosphorescence accompanying the transition from T1, the triplet state T1 has an energy rank different from that of the singlet state S1, and therefore the light wavelength ν is different from the fluorescence accompanying the transition from S1. In addition, the phenomenon of non-radiation that is converted into energy other than light includes those that are converted into thermal energy and those that are deprived of energy by other materials. Chemical substances such as porphyrins (PtTFPP, PtOEP, PdTFPP, etc.) exhibit a so-called quenching phenomenon in which energy is deprived by oxygen. Since the oxygen concentration is proportional to the partial pressure in the atmospheric gas, this establishes the correspondence between luminescence and atmospheric gas pressure, and measures the pressure from the emission state of luminescence (fluorescence / phosphorescence).

In general, the light emission intensity from a pressure-sensitive paint has a characteristic that depends not only on pressure but also on temperature. Therefore, in order to perform pressure measurement with high measurement accuracy, temperature correction of the pressure-sensitive paint is necessary. In particular, when measuring the surface pressure while the temperature of the subject is constantly changing during the experiment, this temperature dependence becomes a large error factor in the airframe model test in a supersonic wind tunnel, for example. Up to now, temperature correction has been performed by attaching a thermocouple to the model and using the detected temperature information, and by dividing pressure-sensitive paint and temperature-sensitive paint separately on the model surface and applying pressure and temperature simultaneously to correct the temperature. There has been a way to do it. However, in the former case, accurate temperature correction is not established if the model temperature is not uniform, and in the latter case, the pressure and temperature at the same location cannot be measured. The pressure and temperature distribution information was measured by dividing the pressure-sensitive paint and the temperature-sensitive paint separately, assuming the symmetry of the phenomenon in the symmetrical structure model. If a pressure-sensitive and temperature-sensitive composite functional paint that can obtain pressure and temperature information can be used, the above-mentioned problems can be cleared and the pressure and temperature distribution on the model surface can be directly measured. That is, by first obtaining temperature data measured with a temperature-sensitive dye that does not have pressure dependency, and correcting the detected data with the pressure-sensitive dye at the same location with this temperature data, pressure measurement without error due to temperature can be performed. It becomes possible. To date, the present inventors have developed a composite paint using PtTFPP as a pressure-sensitive dye, Rhodamin B as a temperature-sensitive dye, and dichloromethane as a solvent, and have obtained certain results. (See Non-Patent Documents 2 and 3) However, this composite paint has the following problems.
1) Since the emission spectra of the two dyes partially overlap, measurement errors due to non-uniformity of the dye dispersion based on the film thickness difference and pressure sensitivity decrease.
2) Since Rhodamin B has an application temperature range of 30 ° C or higher, a temperature lower than this cannot be measured.
3) Since it is a highly volatile solvent, smears are easily formed and the coating surface is rough.
There was a problem.
Yusuke Asai, “Measurement technology of pressure distribution with pressure-sensitive paint”, Visualization Information, Vol. 18 No.69 April 1998 Kazunori Mitsuo, Manabu Hayasaka, Masaharu Kameda, and Keisuke Asai, "Temperature Correction of PSPMeasurement Using Dual-Luminophore Coating," 10th International symposium on Flow Visualization, Kyoto, Aug. 26, 2002 Kazunori Manao, Yasuhiro Egami, Masafumi Hayasaka, Masaharu Kameda, Keisuke Asai, "Visualization of Delta wing surface pressure using a pressure- and temperature-sensitive composite paint," 30th Visualization Information Symposium, Kogakuin University, 2002 July 24th.

  The problem to be solved by the present invention is that a temperature-sensitive paint having an emission wavelength that does not overlap with the emission spectrum of the pressure-sensitive paint and covering the required temperature range, and the temperature-sensitive paint and the pressure-sensitive paint are mixed to form smears. Providing a combination of pressure sensitive and temperature sensitive functional paint that can simultaneously measure pressure and temperature fields at the same position on the model surface used in practical wind tunnel tests. There is to do.

  The pressure-sensitive / temperature-sensitive composite functional paint of the present invention uses a coumarin-based temperature-sensitive dye as a temperature-sensitive material, and a porphyrin (PtTFPP, PtOEP, PdTFPP) containing platinum or palladium as a pressure-sensitive material as a central metal. Etc.), using Poly-IBM-co-TFEM, which is a fluorinated polymer, as the binder and mixing, and using thinner as the solvent.

  The pressure sensitive and temperature sensitive composite functional paint of the present invention is a porcine (PtTFPP, PtOEP, PdTFPP, etc.) having a coumarin-based temperature sensitive pigment as a temperature sensitive material and platinum or palladium as a pressure sensitive material as a central metal. ), The light emission of the pressure sensitive dye and the temperature sensitive dye can be completely separated, and is not affected by measurement errors due to non-uniformity of the dye dispersion. Good measurement can be expected. Since the excitation light for the pressure-sensitive dye and the temperature-sensitive dye can also be used with the same wavelength, the system becomes simple. In addition, the use of coumarin-based temperature-sensitive dyes as temperature-sensitive materials enables measurement in the normal temperature range (near room temperature), provides temperature information necessary for temperature correction of pressure-sensitive dyes, and is suitable for spray coating. It became possible to use thinner having a high volatilization rate. In addition, by using Poly-IBM-co-TFEM, which is a fluoropolymer as a binder, and using thinner as a solvent, a paint mixed with both dyes can be applied to the surface of the specimen without any unevenness and firmly applied. A film can be formed and it is resistant to photodegradation by excitation light, so it can be applied to practical wind tunnel experiments in harsh environments.

  7-Ethylamino-6-methyl-4-trifluormethylcoumarin, a coumarin-based thermosensitive dye, is used as the temperature-sensitive material, Porphyrin (PtTFPP), which is a pressure-sensitive dye, and Poly, a fluoropolymer, as the binder -Isobutylmethacrylate-co-trifluoroethylmethacrylate (abbreviated as Poly-IBM-co-TFEM) is used as a mixed pressure- and temperature-sensitive paint. This pressure- and temperature-sensitive composite functional coating is applied to the surface of a rocket or aircraft model, and the model is mounted in a supersonic wind tunnel to conduct a wind tunnel experiment. The combination of the above-described temperature-sensitive dye, pressure-sensitive dye, and binder allows uniform mixing and uniform application on the model surface to form a firm and stable pressure- and temperature-sensitive composite coating film. The model surface is imaged with a CCD camera in color, and the surface temperature distribution information is first obtained from the intensity distribution by focusing on the light having the emission wavelength of the thermosensitive dye in the image information. Then, based on the obtained temperature information, the light emission information of the pressure-sensitive dye is corrected for the change due to temperature, and accurate pressure distribution information is obtained for the entire model surface on which the film is formed.

Coumarin-based thermosensitive dye (7-Ethylamino-6-methyl-4-trifluormethylcoumarin product name: Coumarin 307) is used as the temperature-sensitive material, and porphyrin (PtTFPP), which is a pressure-sensitive dye, is used as the pressure-sensitive material, and fluorine as the binder. Poly-IBM-co-TFEM, which is a polymer, is mixed, and pressure and sensation using thinner (principal components: toluene, butyl acetate) that is soluble in all materials and does not cause smears. FIG. 1 shows the spectral measurement results of the warm composite function paint. Under atmospheric pressure, the wavelength of the excitation light was 310 to 410 nm, and the type and intensity of the excitation light were the same. The graph shown in (a) is a spectrum when the temperature is set to 10 ° C, 30 ° C, and 50 ° C. Two peaks are shown in the wavelength band of 450 to 500 nm, and other peaks are shown at 650 nm. The short wavelength peak shows the fluorescence characteristics of thermosensitive dye (7-Ethylamino-6-methyl-4-trifluormethylcoumarin), and the long wavelength peak shows the phosphorescence characteristics of the pressure sensitive porphyrin (PtTFPP). . Since both are mixed paints, the characteristics of both are superimposed. The peak value on the long wavelength side is phosphorescence of porphyrin (PtTFPP), which is a pressure-sensitive dye, but the value of this light intensity varies greatly with temperature, indicating that it has temperature dependence. The graph shown in (b) is a spectrum when the temperature is set to 20 ° C. and the pressure is set to 10 kPa, 50 kPa, and 100 kPa. When this graph is observed, the fluorescence of the thermosensitive dye (7-Ethylamino-6-methyl-4-trifluormethylcoumarin) is not dependent on pressure fluctuation and is constant, and the pressure-sensitive dye porphyrin (PtTFPP) phosphor It can be seen that the light changes greatly in response to the pressure change.
Even when other porphins such as PtOEP and PdTFPP are used, the excitation / emission spectrum of the dye is almost the same as this, and can be clearly distinguished from the emission spectrum of the coumarin-based thermosensitive dye.

  As can be seen from the spectral results, it is shown that the emission of the pressure-sensitive dye and the emission of the temperature-sensitive dye are clearly separated. In addition, the emission intensity of the temperature-sensitive dye depends only on temperature, but the emission intensity of the pressure-sensitive dye is affected by both temperature and pressure. Therefore, first, the temperature is detected from the light emission of the temperature-sensitive dye, and the change in the light emission intensity of the pressure-sensitive dye due to the temperature is corrected based on the detected value, and a value corresponding to the pressure can be calculated. FIG. 5 shows the sensitivity characteristics of the temperature-sensitive dye and the pressure-sensitive dye. Coumarin 307 exhibits a substantially linear temperature characteristic without being affected by pressure, and porphyrin (PtTFPP) exhibits a substantially linear change characteristic with respect to pressure while being influenced by temperature. As a demonstration experiment, we introduce the results of measuring the pressure formed when a sonic jet collides with a flat plate. 2 shows the composite paint measurement system of this experiment, in which a coumarin-based thermosensitive dye (7-Ethylamino-6-methyl-4-trifluormethylcoumarin) is applied to the surface of the flat plate 1 as a temperature sensitive material. A coating 2 is formed by applying a pressure-sensitive and temperature-sensitive composite coating material in which porphyrin (PtTFPP), which is a pressure-sensitive dye, is mixed as a material and Poly-IBM-co-TFEM, which is a fluorine-based polymer, is mixed as a binder. The flat plate 1 is provided with a plurality of pressure detection holes 3 in the lateral direction. A nozzle 4 that blows a jet stream, a CCD camera 5 for imaging the light emission state of the flat plate surface, and an excitation light source 6 for exciting the composite paint are installed in front of the flat plate 1 as the subject. Excitation light from the excitation light source 6 was applied to the dye, and light emission of the pressure sensitive dye and light emission of the temperature sensitive dye were measured simultaneously using two CCD cameras 5 equipped with different filters 7. In the figure, 8 is a camera controller, 9 is a timing controller, and 10 is a personal computer that controls the entire system and stores and accumulates information.

  FIG. 3 shows a data image of the pressure field measured using the composite paint of the present invention. It is an image when the jet stream is sprayed from the distance of 8 mm at an angle of 45 ° with respect to the surface of the plane 1. It can be seen that the pressure pattern unique to the impinging jet due to compression and expansion is clearly captured. FIG. 4 is a graph showing the measured values at this time. A is the phosphorescence intensity of porphyrin (PtTFPP) which is a pressure-sensitive dye without temperature correction, and b is the data with temperature correction added thereto. Is displayed. The values plotted with ○ are values obtained by conventional pressure measurement for each of the pressure holes 3, but the temperature corrected data of the composite paint of this example is consistent with the pressure hole data over the entire area. It was proved that the pressure data obtained by obtaining temperature distribution information from the image information using the composite paint of the present invention and temperature-compensating the light emission data of the pressure-sensitive paint based on the obtained information is accurate and highly reliable. In addition, it is significant that the distribution information is continuously obtained over the entire surface of the object, which is impossible with the conventional pressure hole method.

Next, experimental data on coumarin-based thermosensitive dyes other than 7-Ethylamino-6-methyl-4-trifluormethylcoumarin were obtained, and the results are shown below.
(1) 2,3,5,6-1H, 4H-Tetrahydroquinolizino- [9,9a, 1-gh] coumarin (Product name: LAMBDA PHYSIK Coumarin 6H)
(2) 2,3,5,6-1H, 4H-Tetrahydro-8-methylquinolizino- [9,9a, 1-gh] -coumarin (trade name: LAMBDA PHYSIK Coumarin 102)
(3) 2,3,5,6-1H, 4H-Tetrahydro-9-acetylquinolizino- [9,9a, 1-gh] -coumarin (trade name: Coumarin 334, LAMBDA PHYSIK)
(4) 7-Diethylamino-4-trifluormethylcoumarin (trade name: LAMBDA PHYSIK Coumarin 152A (Exciton Coumarin 481)
(5) 2,3,5,6-1H, 4H-Tetrahydro-9- (3-pyridyl) -quinolizino- [9,9a, 1-gh] coumarin (Product name: LAMBDA PHYSIK Coumarin 510)
(6) 3- (2'-Benzimidazolyl) -7-N, N-diethylaminocoumarin (trade name: LAMBDA PHYSIK Coumarin 7)
(7) 2,3,5,6-1H, 4H-Tetrahydro-9-carboethoxyquinolizino- [9,9a, 1-gh] coumarin (Product name: LAMBDA PHYSIK Coumarin314, Exciton Coumarin504)
(8) 3- (2'-N-Methylbenzimidazolyl) -7-N, N-diethylaminocoumarin (trade name: LAMBDA PHYSIK Coumarin30, Exciton Coumarin515)
A temperature-sensitive paint using these coumarins as temperature-sensitive dyes was applied to a substrate to prepare a sample substrate. A fluorine-based polymer was used as the polymer.
The substrate was placed in a chamber where the temperature and pressure could be controlled, and the emitted light was measured with a CCD camera through an optical filter while applying excitation light. The average value of the luminescent image is calculated and graphed. Normalized based on the value of 10 ℃. FIG. 6 and FIG. 7 show the temperature sensitivity characteristics obtained for the coumarin dyes. 6 (a) is sample number 5, (b) is sample number 6, (c) is sample number 7, (d) is sample number 8, (e) is sample number 1, and (f) is sample number 2. It is a characteristic. 7A shows the characteristics of sample number 3 and FIG. 7B shows the characteristics of sample number 4. As with the previous coumarin 307, when the temperature is changed, the emission intensity ratio is changed, which is dependent on the temperature and the sensitivity (inclination of the straight line) does not depend on the pressure.

The result of measuring the fluorescence peak of the coumarin dye by spectroscopic measurement is shown below.
Sample number 1 (C6H): fluorescence spectrum maximum value ... 446.4 nm
Sample number 2 (C102): fluorescence spectrum maximum value ... 441.6nm
Sample number 3 (C344): fluorescence spectrum maximum value ... 487.6 nm
Sample No. 4 (C481): Maximum fluorescence spectrum ... 462.8nm
Sample No. 5 (C510): Maximum fluorescence spectrum ... 479.0 nm
Sample No. 6 (C7): Maximum fluorescence spectrum ... 488.4 nm
Sample No. 7 (C504): fluorescence spectrum maximum value ... 476.4 nm
Sample No. 8 (C515): fluorescence spectrum maximum value ... 473.4 nm
It is far from light emission of pressure sensitive dye (PtTFPP) used as a composite material, and has good wavelength separation. The emission peak of pressure sensitive dye (PtTFPP) is 650 nm.

  FIG. 8 shows the results of irradiating excitation light for 1 hour under the conditions of 20 ° C. and 100 kPa and monitoring the change in the emission intensity. If the dye deteriorates, the light emission should be weakened. However, as can be seen from FIG. 8, the light emission intensity hardly changed for both the temperature-sensitive dye and the pressure-sensitive dye. That is, it is resistant to deterioration. Other coumarin dyes are similarly resistant to degradation. As a result of the above verification, it was proved that a coumarin-based thermosensitive dye is an appropriate material as a thermosensitive material used in a pressure / temperature-sensitive composite functional coating.

It is a graph which shows the spectral characteristics of the composite function coating material concerning this invention, (a) shows temperature dependence, (b) shows pressure dependence. It is a block diagram of the measurement system used for the characteristic test of the composite function coating material concerning this invention. It is a pressure distribution image in the characteristic test of the composite functional paint performed by said measurement system. The data obtained by the above experiment is compared with the pressure hole data. (A) is a graph which shows the temperature sensitivity characteristic of the coumarin dye used for the Example of this invention, (b) is a graph which shows the pressure sensitivity characteristic of the pressure sensitive dye used by this invention. In order to confirm the appropriateness as a thermosensitive dye of this invention, it is a graph which shows the thermosensitive characteristic about the sample of a coumarin type | system | group dye. In order to confirm the appropriateness as a thermosensitive dye of this invention, it is a graph which shows the thermosensitive characteristic about the sample of a coumarin type | system | group dye. (A) is a graph showing degradation characteristics of a coumarin-based thermosensitive dye 307, and (b) is a graph showing degradation characteristics of a porphyrin (PtTFPP) which is a pressure-sensitive dye. It is a figure explaining the prior art which divided the pressure sensitive paint and the temperature sensitive paint on the model surface, and applied separately and measured pressure and temperature simultaneously.

Explanation of symbols

1 Flat plate 6 Excitation light source
2 Coating 7 Filter 3 Pressure hole 8 Camera controller 4 Nozzle 9 Timing controller
5 CCD camera 10 Personal computer

Claims (5)

  Pressure sensitive / temperature sensitive composite functional paint using pressure sensitive dye platinum or palladium-based porphyrin as pressure sensitive material, using coumarin-based temperature sensitive dye as combined temperature sensitive material・ Temperature sensitive composite paint.   The pressure- and temperature-sensitive composite functional paint according to claim 1, wherein PtTFPP is used as palladium having platinum or palladium as a central metal.   The pressure- and temperature-sensitive composite functional paint according to claim 1 or 2, which is a mixture obtained by adopting Poly-IBM-co-TFEM which is a fluorine-based polymer as a binder.   The pressure- and temperature-sensitive composite paint according to claim 3, wherein thinner is used as the solvent.   The pressure- and temperature-sensitive composite paint according to any one of claims 1 to 4, wherein 7-Ethylamino-6-methyl-4-trifluormethylcoumarin is used as a coumarin-based temperature-sensitive dye.